In this handout image provided by the News1-Dong-A Ilbo, North Korean officials watch the demolition of the Punggye-ri nuclear test site on May 24, 2018 in Punggye-ri, North Korea.

U.S. banks and regulators continue to struggle tracking and curbing money moved through international banks and companies that ultimately is used to fund the North Korean government, according to a report in the The Wall Street Journal.

That’s because North Korea uses proxies with hidden government ties across the globe to facilitate moving those payments, according to the report.

North Korea is able to sell goods using a multi-step process, that starts with selling goods to an overseas company, according to court documents cited by The Journal’s report. The overseas firm doesn’t pay North Korea directly, but a third company as directed by the Pyongyang government. Then, a U.S. bank processes the wire transfer from the purchasing company to the third party.

The third company then pays a supplier for goods needed in North Korea, and the items are sent to the country without any money actually flowing through it, the report says.

U.S. officials also said North Korea is increasingly breaking its payments into smaller chunks to avoid detection, the publication reported.

The Journal reporting comes as the U.S. has tried to tighten the screws on Pyongyang to force it to renounce its weapons of mass destruction, even as President Donald Trump pursues high level talks with North Korean leader Kim Jong Un.

Last year, the Trump administration signed an executive order giving the Treasury Department broader powers to sanction entities that are tied to these North Korea-linked transactions. Earlier this year, the Treasury Department also released information describing how North Korea uses deceptive labeling of cargo ships in order to facilitate the transfer of goods into the country.

The Wall Street Journal’s full report can be found on its website (note subscription may be required).